A few decades ago your only prescription options for a good night's sleep were benzodiazepine hypnotics like Xanax or Halcion. These pills are still widely prescribed, but patients today have more choices: Similar medications called nonbenzodiazepines and an even newer drug that stands alone in its own class.

When you just need some shut-eye, though, having multiple options can make things even more complicated and confusing. Here are some quick descriptions to help you sort through the main differences and similarities.

Benzodiazepines

Include older drugs such as Valium, Klonopin, Xanax, and Halcion

Induce sleep by slowing down the central nervous system

Are often used to treat anxiety and panic disorders as well as insomnia

Are approved for short-term use (a few weeks or less) by adults, though many doctors prescribe them for longer

Cost less than the newer medicationsin some cases, about 75 cents a pillbecause they are available as generics.

Have a low risk of abuse or dependence (although slightly higher than other sleep medications)

Can cause side effects such as: residual daytime sleepiness, cognitive impairment, memory loss, falling and motor impairment (especially among older people), and the return, or "rebound," of insomnia after abruptly discontinuing a drug

In a 2006 government-sponsored analysis, benzodiazepines caused patients to fall asleep 10 minutes faster and sleep 32 minutes longer than those who took placebo pills.

Nonbenzodiazepines

Include popular sleep medications Ambien, Lunesta, and Sonata

Target the same brain receptors as do benzodiazepines, but in a slightly more specific manner

Are now recommended as the first-choice medications for short-term insomnia

Include medications (Lunesta and Ambien CR) that have been studied for up to six months and are FDA-approved for long-term use in adults

Usually cost more than their older benzodiazepine counterpartsup to $4 a pillbecause most are not available as generics (exception: zolpidem, better known by its brand name, Ambien)

Are safer than benzodiazepines for people with breathing problems, but can still aggravate sleep apnea and other conditions

Have a lower risk for abuse or dependence than benzodiazepines

Typically cause fewer side effects associated with older sleeping pillssuch as daytime sleepiness, or the return of insomnia if you abruptly stop taking the drugbecause they have a shorter half-life and don't stay in the body for as many hours

Have been linked to nocturnal behaviors of which the pill taker has no memorysuch as eating, walking, or even driving while asleep. Many doctors believe these drugs have been unfairly singled out (over the older benzodiazepines) because they're prescribed so often

In a 1999 government-sponsored analysis, nonbenzodiazepines caused patients to sleep better and longer than those who took the placebos

The stand-alone: Rozerem

Was approved by the FDA in 2005 for use by insomniacs who have trouble falling asleep

Mimics the actions of the brain's melatonin hormone, shutting down alert signals and helping the body transition into sleep

Is approved for long-term use in adults

Shows no evidence of abuse or tolerance in clinical studies

Costs more than older benzodiazepinesabout $3.50 a pilland is not available as a generic

Has not been studied in patients with sleep apnea or related breathing disorders

Can cause side effects such as: headache, daytime sleepiness, and dizziness

Has been associated with altered hormone levels, which may cause rare sexual side effects.

In a 2006 government-sponsored analysis, Rozerem caused patients to fall asleep seven to 16 minutes faster than a placebo and increased total sleep time 11 to 19 minutes.